When I was a young mother, I decided to get my certification as a Master Gardener, and in one of the classes our instructor gave us an overview of grafting. Now, I have to admit, I’ve never been particularly science-minded, but I found this discussion to be unabashedly fascinating. You take parts of two similar plants (called rootstock and scion) and graft them together to create a new plant that has the characteristics and traits you desire.
In this article, we’re talking about rootstock — what it is, how it’s chosen, and what kind of plants are typically used. Dive in and get your geek on — it’s pretty amazing!
WHAT IS ROOTSTOCK?
What is rootstock? Rootstock is the base and root portion of a grafted plant. It’s grafted onto the scion, which is the flowering or fruiting part of the plant, in order to create a new plant with superior qualities.
How are rootstock plants chosen? Rootstock plants must have a close relation to the scion in order for the graft to be successful. An apple rootstock cannot be grafted with a pit fruit like cherry, for example. Grafters look for naturally growing trees, a naturally occurring plant mutation, or a genetically bred plant to use as rootstock. And once a successful rootstock plant is identified, there is much rejoicing, as there are many more scion varieties available than rootstock ones.
Why do we use rootstock? Mostly to create very specific plant traits. Rootstock plants determine the longevity of the plant, resistance to pests and diseases, cold hardiness, fruit yield, and the size of the tree and its root system. Also, fruit trees grown from rootstock tend to produce trees that immediately fruit, rather than the 3-8 years it takes to get fruit from a tree grown from seed. Take a larger fruit tree, for example — when it’s grafted onto the rootstock of a dwarf fruit tree, the result will be smaller trees that home gardeners can grow in containers, and with an immediate fruit harvest.
What kind of plants are used? In the grafting world, it’s the fruit crops (citrus, apples, etc.) that pay close attention to rootstock, but other plants like roses and ornamental trees also use rootstock to produce new variations. Have you seen those Knockout rose plants that look like standard trees with a single trunk? That’s a result of grafting, not painstaking pruning.